TY - JOUR T1 - Intraoperative transfusion in older patients with low preoperative haematocrit levels and substantial blood loss during major non-cardiac surgery is associated with lower 30-day postoperative mortality JF - Evidence Based Medicine JO - Evid Based Med SP - 185 LP - 186 DO - 10.1136/ebm1137 VL - 15 IS - 6 AU - Jeffrey L Carson AU - Sarang Kim Y1 - 2010/12/01 UR - http://ebm.bmj.com/content/15/6/185.abstract N2 - Commentary on: Wu WC, Smith TS, Henderson WG, et al. Operative blood loss, blood transfusion, and 30-day mortality in older patients after major noncardiac surgery. Ann Surg 2010;252:11–17.OpenUrlCrossRefPubMedWeb of Science More than 81 million red blood cell units are collected annually throughout the world.1 Yet the indications for transfusion in most settings are unknown. Clinical trials in surgical patients have generally compared transfusion strategies at two haemoglobin concentrations and have not evaluated intraoperative transfusions. Thus, this analysis is unique. A retrospective cohort study was performed in about 240 000 patients of 65 years of age and older who underwent non-cardiac surgery. Intraoperative blood loss was estimated from the preoperative haematocrit, lowest postoperative haematocrit and amount of blood transfused intraoperatively. A priori, preoperative haematocrit was categorised into four levels: <24%, 24–29.9%, 30–35.9% and ≥36%, and estimated blood loss was stratified into <500, 500–999 and ≥1000 cc. A propensity score was developed to predict each patient's probability of receiving an intraoperative transfusion. Patients … ER -